scholarly journals A Hypothesis, Unifying the Structure and the Entropy of the Universe

1972 ◽  
Vol 160 (1) ◽  
pp. 1P-3P ◽  
Author(s):  
Y. B. Zeldovich
Keyword(s):  
The Universe ◽  
Entropy Of The Universe

scholarly journals Estimate of energy constituents of the universe in ΛCDM

2017 ◽  
Vol 95 (1) ◽  
pp. 21-24
Author(s):  
Jung-Jeng Huang ◽  
Meng-Jong Wang
Keyword(s):  
Maximal Entropy ◽  
Extended Version ◽  
Cosmic Scale ◽  
Λcdm Model ◽  
The Universe ◽  
Entropy Of The Universe

We propose that the Hubble law can be viewed as the de Broglie relation on a cosmic scale. We show how the entropy of the Universe can be estimated in the ΛCDM model and its extended version, and how the quest for the maximal entropy leads to the energy constituents of the current Universe.

Evolution of the universe from the perspective of entropy and information

2021 ◽  
pp. 2150111
Author(s):  
Fei-Quan Tu ◽  
Bin Sun ◽  
Meng Wan ◽  
Qi-Hong Huang
Keyword(s):  
Information Entropy ◽  
Second Law Of Thermodynamics ◽  
Boltzmann Entropy ◽  
Evolution Of The Universe ◽  
Thermodynamic Entropy ◽  
Entire Universe ◽  
Low Entropy ◽  
The Relationship ◽  
The Universe ◽  
Entropy Of The Universe

Entropy is a key concept widely used in physics and other fields. At the same time, the meaning of entropy with different names and the relationship among them are confusing. In this paper, we discuss the relationship among the Clausius entropy, Boltzmann entropy and information entropy and further show that the three kinds of entropy are equivalent to each other to some extent. Moreover, we point out that the evolution of the universe is a process of entropy increment and life originates from the original low entropy of the universe. Finally, we discuss the evolution of the entire universe composed of the cosmological horizon and the space surrounded by it and interpret the entropy as a measure of information of all microstates corresponding to a certain macrostate. Under this explanation, the thermodynamic entropy and information entropy are unified and we can conclude that the sum of the entropy of horizon and the entropy of matter in the space surrounded by the horizon does not decrease with time if the second law of thermodynamics holds for the entire universe.

scholarly journals A LARGER ESTIMATE OF THE ENTROPY OF THE UNIVERSE

2010 ◽  
Vol 710 (2) ◽  
pp. 1825-1834 ◽  
Author(s):  
Chas A. Egan ◽  
Charles H. Lineweaver
Keyword(s):  
The Universe ◽  
Entropy Of The Universe

scholarly journals What is the entropy of the universe?

2009 ◽  
Vol 26 (14) ◽  
pp. 145005 ◽  
Author(s):  
Paul H Frampton ◽  
Stephen D H Hsu ◽  
Thomas W Kephart ◽  
David Reeb
Keyword(s):  
The Universe ◽  
Entropy Of The Universe

scholarly journals Entropy of the Universe

2009 ◽  
Vol 48 (7) ◽  
pp. 1933-1936 ◽  
Author(s):  
Marcelo Samuel Berman
Keyword(s):  
The Universe ◽  
Entropy Of The Universe

Expanding Universe with a Variable Cosmological Term

2015 ◽  
Vol 70 (11) ◽  
pp. 905-911 ◽  
Author(s):  
Carlos Blanco-Pérez ◽  
Antonio Fernández-Guerrero
Keyword(s):  
Cosmological Constant ◽  
Cosmological Term ◽  
Expanding Universe ◽  
Einstein’S Field Equations ◽  
Field Equations ◽  
Variable Cosmological Term ◽  
Einstein's Field Equations ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Entropy Of The Universe

AbstractWe propose a model of expansion of the universe in which a minimal, ‘quantised’ rate is dependent upon the value of the cosmological constant Λ in Einstein’s field equations, itself not a constant but a function of the size and the entropy of the universe. From this perspective, we offer an expression which relates Hubble’s constant with the cosmological constant.

scholarly journals Thermodynamic constraints on matter creation models

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
R. Valentim ◽  
J. F. Jesus
Keyword(s):  
Dark Matter ◽  
Event Horizon ◽  
Thermodynamic Equilibrium ◽  
Cold Dark Matter ◽  
Apparent Horizon ◽  
Total Entropy ◽  
De Sitter ◽  
Derivatives Of ◽  
The Universe ◽  
Entropy Of The Universe

AbstractEntropy is a fundamental concept from Thermodynamics and it can be used to study models on context of Creation Cold Dark Matter (CCDM). From conditions on the first ($$\dot{S}\ge 0$$ S ˙ ≥ 0 ) (throughout the present work we will use dots to indicate time derivatives and dashes to indicate derivatives with respect to scale factor) and second order ($$\ddot{S}<0$$ S ¨ < 0 ) time derivatives of total entropy in the initial expansion of Sitter through the radiation and matter eras until the end of Sitter expansion, it is possible to estimate the intervals of parameters. The total entropy ($$S_{t}$$ S t ) is calculated as sum of the entropy at all eras ($$S_{\gamma }$$ S γ and $$S_{m}$$ S m ) plus the entropy of the event horizon ($$S_h$$ S h ). This term derives from the Holographic Principle where it suggests that all information is contained on the observable horizon. The main feature of this method for these models are that thermodynamic equilibrium is reached in a final de Sitter era. Total entropy of the universe is calculated with three terms: apparent horizon ($$S_{h}$$ S h ), entropy of matter ($$S_{m}$$ S m ) and entropy of radiation ($$S_{\gamma }$$ S γ ). This analysis allows to estimate intervals of parameters of CCDM models.

scholarly journals Birth of the GUP and its effect on the entropy of the universe in Lie-N-algebra

2017 ◽  
Vol 14 (09) ◽  
pp. 1750130 ◽  
Author(s):  
Alireza Sepehri ◽  
Anirudh Pradhan ◽  
Richard Pincak ◽  
Farook Rahaman ◽  
A. Beesham ◽  
...  
Keyword(s):  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
Dimensional Theory ◽  
Spinor Fields ◽  
Quantum Numbers ◽  
The Creation ◽  
Derivatives Of ◽  
The Universe ◽  
Entropy Of The Universe

In this paper, the origin of the generalized uncertainty principle (GUP) in an [Formula: see text]-dimensional theory with Lie-[Formula: see text]-algebra is considered. This theory which we name Generalized Lie-[Formula: see text]-Algebra (GLNA)-theory can be reduced to [Formula: see text]-theory with [Formula: see text] and [Formula: see text]. In this theory, at the beginning, two energies with positive and negative signs are created from nothing and produce two types of branes with opposite quantum numbers and different numbers of timing dimensions. Coincidence with the birth of these branes, various derivatives of bosonic fields emerge in the action of the system which produce the [Formula: see text] GUP for bosons. These branes interact with each other, compact and various derivatives of spinor fields appear in the action of the system which leads to the creation of the GUP for fermions. The previous predicted entropy of branes in the GUP is corrected as due to the emergence of higher orders of derivatives and different number of timing dimensions.

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